Send a Blur notification to the renderer if we receive a mouse exit for a window outside a popup.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 93a4e9342c83c61eb30838eba8bed682347c9ce1..1457ae436b8b6c9381fb234e5f004b6232021389 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -337,6 +337,12 @@ void RenderWidgetHostViewAura::ApplyEventFilterForPopupExit(
   if (target != window_ &&
       (!popup_parent_host_view_ ||
        target != popup_parent_host_view_->window_)) {
+    // If we enter this code path it means that we did not receive any focus
+    // lost notifications for the popup window. Ensure that blink is aware
+    // of the fact that focus was lost for the host window by sending a Blur
+    // notification.
+    if (popup_parent_host_view_ && popup_parent_host_view_->host_)
+      popup_parent_host_view_->host_->Blur();
     // Note: popup_parent_host_view_ may be NULL when there are multiple
     // popup children per view. See: RenderWidgetHostViewAura::InitAsPopup().
     Shutdown();